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// Copyright 2016 The Xorm Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package xorm
import (
"database/sql"
"errors"
"fmt"
"reflect"
"strconv"
"github.com/go-xorm/core"
)
// Get retrieve one record from database, bean's non-empty fields
// will be as conditions
func (session *Session) Get(bean interface{}) (bool, error) {
if session.isAutoClose {
defer session.Close()
}
return session.get(bean)
}
func (session *Session) get(bean interface{}) (bool, error) {
beanValue := reflect.ValueOf(bean)
if beanValue.Kind() != reflect.Ptr {
return false, errors.New("needs a pointer to a value")
} else if beanValue.Elem().Kind() == reflect.Ptr {
return false, errors.New("a pointer to a pointer is not allowed")
}
if beanValue.Elem().Kind() == reflect.Struct {
if err := session.statement.setRefBean(bean); err != nil {
return false, err
}
}
var sqlStr string
var args []interface{}
var err error
if session.statement.RawSQL == "" {
if len(session.statement.TableName()) <= 0 {
return false, ErrTableNotFound
}
session.statement.Limit(1)
sqlStr, args, err = session.statement.genGetSQL(bean)
if err != nil {
return false, err
}
} else {
sqlStr = session.statement.RawSQL
args = session.statement.RawParams
}
table := session.statement.RefTable
if session.canCache() && beanValue.Elem().Kind() == reflect.Struct {
if cacher := session.engine.getCacher(table.Name); cacher != nil &&
!session.statement.unscoped {
has, err := session.cacheGet(bean, sqlStr, args...)
if err != ErrCacheFailed {
return has, err
}
}
}
context := session.statement.context
if context != nil {
res := context.Get(fmt.Sprintf("%v-%v", sqlStr, args))
if res != nil {
structValue := reflect.Indirect(reflect.ValueOf(bean))
structValue.Set(reflect.Indirect(reflect.ValueOf(res)))
session.lastSQL = ""
session.lastSQLArgs = nil
return true, nil
}
}
has, err := session.nocacheGet(beanValue.Elem().Kind(), table, bean, sqlStr, args...)
if err != nil || !has {
return has, err
}
if context != nil {
context.Put(fmt.Sprintf("%v-%v", sqlStr, args), bean)
}
return true, nil
}
func (session *Session) nocacheGet(beanKind reflect.Kind, table *core.Table, bean interface{}, sqlStr string, args ...interface{}) (bool, error) {
rows, err := session.queryRows(sqlStr, args...)
if err != nil {
return false, err
}
defer rows.Close()
if !rows.Next() {
if rows.Err() != nil {
return false, rows.Err()
}
return false, nil
}
switch bean.(type) {
case sql.NullInt64, sql.NullBool, sql.NullFloat64, sql.NullString:
return true, rows.Scan(&bean)
case *sql.NullInt64, *sql.NullBool, *sql.NullFloat64, *sql.NullString:
return true, rows.Scan(bean)
}
switch beanKind {
case reflect.Struct:
fields, err := rows.Columns()
if err != nil {
// WARN: Alougth rows return true, but get fields failed
return true, err
}
scanResults, err := session.row2Slice(rows, fields, bean)
if err != nil {
return false, err
}
// close it before covert data
rows.Close()
dataStruct := rValue(bean)
_, err = session.slice2Bean(scanResults, fields, bean, &dataStruct, table)
if err != nil {
return true, err
}
return true, session.executeProcessors()
case reflect.Slice:
err = rows.ScanSlice(bean)
case reflect.Map:
err = rows.ScanMap(bean)
default:
err = rows.Scan(bean)
}
return true, err
}
func (session *Session) cacheGet(bean interface{}, sqlStr string, args ...interface{}) (has bool, err error) {
// if has no reftable, then don't use cache currently
if !session.canCache() {
return false, ErrCacheFailed
}
for _, filter := range session.engine.dialect.Filters() {
sqlStr = filter.Do(sqlStr, session.engine.dialect, session.statement.RefTable)
}
newsql := session.statement.convertIDSQL(sqlStr)
if newsql == "" {
return false, ErrCacheFailed
}
tableName := session.statement.TableName()
cacher := session.engine.getCacher(tableName)
session.engine.logger.Debug("[cacheGet] find sql:", newsql, args)
table := session.statement.RefTable
ids, err := core.GetCacheSql(cacher, tableName, newsql, args)
if err != nil {
var res = make([]string, len(table.PrimaryKeys))
rows, err := session.NoCache().queryRows(newsql, args...)
if err != nil {
return false, err
}
defer rows.Close()
if rows.Next() {
err = rows.ScanSlice(&res)
if err != nil {
return false, err
}
} else {
return false, ErrCacheFailed
}
var pk core.PK = make([]interface{}, len(table.PrimaryKeys))
for i, col := range table.PKColumns() {
if col.SQLType.IsText() {
pk[i] = res[i]
} else if col.SQLType.IsNumeric() {
n, err := strconv.ParseInt(res[i], 10, 64)
if err != nil {
return false, err
}
pk[i] = n
} else {
return false, errors.New("unsupported")
}
}
ids = []core.PK{pk}
session.engine.logger.Debug("[cacheGet] cache ids:", newsql, ids)
err = core.PutCacheSql(cacher, ids, tableName, newsql, args)
if err != nil {
return false, err
}
} else {
session.engine.logger.Debug("[cacheGet] cache hit sql:", newsql, ids)
}
if len(ids) > 0 {
structValue := reflect.Indirect(reflect.ValueOf(bean))
id := ids[0]
session.engine.logger.Debug("[cacheGet] get bean:", tableName, id)
sid, err := id.ToString()
if err != nil {
return false, err
}
cacheBean := cacher.GetBean(tableName, sid)
if cacheBean == nil {
cacheBean = bean
has, err = session.nocacheGet(reflect.Struct, table, cacheBean, sqlStr, args...)
if err != nil || !has {
return has, err
}
session.engine.logger.Debug("[cacheGet] cache bean:", tableName, id, cacheBean)
cacher.PutBean(tableName, sid, cacheBean)
} else {
session.engine.logger.Debug("[cacheGet] cache hit bean:", tableName, id, cacheBean)
has = true
}
structValue.Set(reflect.Indirect(reflect.ValueOf(cacheBean)))
return has, nil
}
return false, nil
}